New zodiac signs 2011: Can one guy just change the zodiac like that?

A newspaper interview with an astronomer has rocked the astrological world, leading some believers to worry that they've been referring to themselves as the "wrong" sign for all these years, and that instead of being, say, sensitive, dependable, and stubborn, they are now emotional, reliable, and obdurate.

In an interview with the Minneapolis-St. Paul Star Tribune, Parke Kunkle of the Minnesota Planetarium Society explained something astronomers have known for millenia: that the sun doesn't actually rise and fall through the constellations on the dates that your horoscope says that it does, and that it actually passes through a 13th constellation, Ophiuchus, the Snake Annoyer.

Can one man unilaterally change the zodiac? Just because Mr. Kunkle thinks you are now an Ophiuchus and not a Sagittarius, should we all just throw away our quivers and stomp our hooves in astrological outrage?

Actually, Kunkle didn’t change anything at all. All he did was explain what is actually happening in the night sky – which is sort of what astronomers do.

Here we, too, will try to explain the science behind the celestial kerfuffle. Just don’t get angry at us for slighting your favorite constellation.

Astronomically speaking, the zodiac is simply a way of plotting the movement of the sun against the stars behind it. When Babylonian sky-watchers thousands of years ago recorded the course of the sun in the sky for a year, they discovered that the sun moves through only a few of the dozens of charted constellations.

These constellations are the constellations of the zodiac.

But the astrological version of the zodiac was never astronomically accurate, and has become less so over time.

• The sun actually moves through 13 constellations, but the numerologically inclined Babylonians opted to go with a more auspicious 12. The constellation left out: Ophiuchus.

• The calendar for the zodiac was also set up for simplicity, not astronomical accuracy. So each of the 12 constellations of the zodiac was arbitrarily assigned a full month – one-twelfth of the sun’s yearly path – when, in fact, the path of the sun means it might only graze some constellations briefly while passing right through the middle of others.

• Finally, thanks to the gravitational pull of the moon and the sun, the Earth wobbles on its axis a bit, meaning that the sun’s path through the stars over the course of a year appears slightly different from the way it did 3,000 years ago when the zodiac was devised, resulting in a one-month shift in the stars' alignments. The earth's axis takes about 26,000 years to go full circle.

All Kunkle was doing – as many astronomers have done before him – was telling people astronomy’s take on the zodiac. In other words, he was answering a very simple astronomical question: When is the sun in which constellation?

Given that astronomers have set up formal boundaries for every constellation in the sky, it is possible to answer this with perfect accuracy. The result is of this astronomical clarity, though, is astrological chaos.

All this is old news, but for some reason, the story went viral this time, leading millions to search for their "new" astrological sign. Kunkle, whose comments were not based on any new research, told the Star-Tribune that he was surprised at the sudden attention.

Astronomers have been telling the world that astrology is a load of tosh for centuries. Why are people suddenly listening this time? Perhaps the stars were aligned.